Apparatuses for generating neutrons

Abstract

An apparatus for generating neutrons may include: a hollow casing configured to rotate about a central axis, the casing including a wall having a central region substantially at the central axis and a peripheral region, wherein the wall defines a cavity, and wherein the cavity is configured to contain a first coolant fluid; an active layer at least partially on the peripheral region external to the cavity, wherein the active layer is configured to realize a neutron-generating reaction; at least one particle accelerator configured to direct an ion beam on the active layer to activate the neutron-generating reaction; movement means configured to rotate the casing about the central axis and to force the first coolant fluid to contact the wall at the active layer for cooling the casing; and external cooling including a second coolant fluid contacting at least an external portion of the wall.

The invention claimed is: 
     
       1. An apparatus for generating neutrons, the apparatus comprising:
 a hollow casing having a central axis and configured to rotate about the central axis, the hollow casing comprising a wall having a central region substantially at the central axis and a peripheral region external to the central region, wherein the wall defines a cavity, and wherein the cavity is configured to contain a first coolant fluid; 
 an active layer at least partially on the peripheral region external to the cavity, wherein the active layer is configured to realize a neutron-generating reaction; 
 at least one particle accelerator configured to direct an ion beam on the active layer to activate the neutron-generating reaction; 
 movement means configured to rotate the hollow casing about the central axis and to force the first coolant fluid to contact an internal surface of the wall at the active layer for cooling the hollow casing; and 
 external cooling means configured to externally cool the hollow casing, wherein the external cooling means comprises a second coolant fluid contacting at least an external portion of the wall; 
 wherein the hollow casing is sealed with respect to an external environment to retain the first coolant fluid within the cavity and to prevent the second coolant fluid from mixing with the first coolant fluid, and 
 wherein the first coolant fluid transfers heat through the wall of the hollow casing directly to the second coolant fluid. 
 
     
     
       2. The apparatus of  claim 1 , wherein the hollow casing extends longitudinally along the central axis between a first end and a second end, the hollow casing further comprising:
 a disc portion at the first end, the disc portion having an upper surface, a lower surface, and an edge between the upper surface and the lower surface, wherein the upper surface, the lower surface, and the edge define at least in part the wall; and 
 a truncated-cone portion extended along the central axis from the lower surface to the second end, the truncated-cone portion having a base at the second end and a side wall connected to the base and to the lower surface of the disc portion, wherein the base and the side wall define at least in part the wall. 
 
     
     
       3. The apparatus of  claim 2 , wherein the truncated-cone portion is tapered to direct the first coolant fluid into the disc portion at the edge. 
     
     
       4. The apparatus of  claim 2 , wherein the active layer is on the disc portion near the edge. 
     
     
       5. The apparatus of  claim 2 , further comprising:
 a seat near the active layer; 
 wherein the seat is configured to retain a sample to be irradiated. 
 
     
     
       6. The apparatus of  claim 5 , wherein the edge of the disc portion has a circumferential recess defining the seat. 
     
     
       7. The apparatus of  claim 2 , further comprising:
 vacuum-sealing means fixed with respect to the hollow casing and configured to maintain vacuum between the at least one particle accelerator and at least the disc portion to realize the neutron-generating reaction. 
 
     
     
       8. The apparatus of  claim 7 , wherein the vacuum-sealing means comprises:
 at least one rotating seal configured to maintain the vacuum externally with respect to the disc portion of the hollow casing. 
 
     
     
       9. The apparatus of  claim 2 , wherein the central axis of the hollow casing is substantially vertical, and
 wherein the disc portion is above the truncated-cone portion. 
 
     
     
       10. The apparatus of  claim 1 , wherein the apparatus is configured to maintain the second coolant fluid at lower temperature than the first coolant fluid. 
     
     
       11. The apparatus of  claim 1 , wherein the first coolant fluid comprises water. 
     
     
       12. The apparatus of  claim 2 , wherein when the movement means rotates the hollow casing, centrifugal force causes a liquid phase of the first coolant fluid to move from the truncated-cone portion toward the disc portion. 
     
     
       13. The apparatus of  claim 1 , wherein the hollow casing extends longitudinally along the central axis between a first end and a second end,
 wherein rotation of the hollow casing causes a liquid phase of the first coolant fluid to move from the second end toward the first end, and 
 wherein a pressure difference between the first end and the second end causes a vapor phase of the first coolant fluid to move from the first end toward the second end. 
 
     
     
       14. The apparatus of  claim 1 ,
 wherein the hollow casing extends longitudinally along the central axis between a first end and a second end, 
 wherein at the first end, the first coolant fluid undergoes a first phase change from a liquid phase to a vapor phase, 
 wherein at the second end, the first coolant fluid undergoes a second phase change from the vapor phase to the liquid phase, and 
 wherein a pressure difference caused by the first and second phase changes causes the vapor phase of the first coolant fluid to move from the first end toward the second end. 
 
     
     
       15. An apparatus for generating neutrons, the apparatus comprising:
 a hollow casing having a central axis and configured to rotate about the central axis, the hollow casing comprising a wall having a central region substantially at the central axis and a peripheral region external to the central region, wherein the wall defines a cavity, and wherein the cavity is configured to contain a first coolant fluid; 
 an active layer at least partially on the peripheral region external to the cavity, wherein the active layer is configured to realize a neutron-generating reaction; 
 at least one particle accelerator configured to direct an ion beam on the active layer to activate the neutron-generating reaction; 
 movement means configured to rotate the hollow casing about the central axis and to force the first coolant fluid to contact an internal surface of the wall at the active layer for cooling the hollow casing; and 
 external cooling means configured to externally cool the hollow casing, wherein the external cooling means comprises a second coolant fluid contacting at least an external portion of the wall; 
 wherein the hollow casing is sealed with respect to an external environment to retain the first coolant fluid within the cavity, 
 wherein the hollow casing extends longitudinally along the central axis between a first end and a second end, the hollow casing further comprising:
 a disc portion at the first end, the disc portion having an upper surface, a lower surface, and an edge between the upper surface and the lower surface, wherein the upper surface, the lower surface, and the edge define at least in part the wall; and 
 a truncated-cone portion extended along the central axis from the lower surface to the second end, the truncated-cone portion having a base at the second end and a side wall connected to the base and to the lower surface of the disc portion, wherein the base and the side wall define at least in part the wall; 
 
 wherein the cavity is defined by the disc portion and by the truncated-cone portion, and 
 wherein the movement means is configured to push the first coolant fluid from the truncated-cone portion to the disc portion. 
 
     
     
       16. The apparatus of  claim 15 , wherein the apparatus is configured to maintain the second coolant fluid at lower temperature than the first coolant fluid. 
     
     
       17. The apparatus of  claim 15 , wherein the first coolant fluid comprises water. 
     
     
       18. An apparatus for generating neutrons, the apparatus comprising:
 a hollow casing having a central axis and configured to rotate about the central axis, the hollow casing comprising a wall having a central region substantially at the central axis and a peripheral region external to the central region, wherein the wall defines a cavity, and wherein the cavity is configured to contain a first coolant fluid; 
 an active layer at least partially on the peripheral region external to the cavity, wherein the active layer is configured to realize a neutron-generating reaction; 
 at least one particle accelerator configured to direct an ion beam on the active layer to activate the neutron-generating reaction; 
 movement means configured to rotate the hollow casing about the central axis and to force the first coolant fluid to contact an internal surface of the wall at the active layer for cooling the hollow casing; and 
 external cooling means configured to externally cool the hollow casing, wherein the external cooling means comprises a second coolant fluid contacting at least an external portion of the wall; 
 wherein the hollow casing is sealed with respect to an external environment to retain the first coolant fluid within the cavity, 
 wherein the hollow casing extends longitudinally along the central axis between a first end and a second end, the hollow casing further comprising:
 a disc portion at the first end, the disc portion having an upper surface, a lower surface, and an edge between the upper surface and the lower surface, wherein the upper surface, the lower surface, and the edge define at least in part the wall; and 
 a truncated-cone portion extended along the central axis from the lower surface to the second end, the truncated-cone portion having a base at the second end and a side wall connected to the base and to the lower surface of the disc portion, wherein the base and the side wall define at least in part the wall; 
 
 wherein the base of the truncated-cone portion has a first diameter, 
 wherein the side wall of the truncated-cone portion defines a connecting edge opposite to the base, wherein the truncated-cone portion is connected to the lower surface of the disc portion at the connecting edge, and wherein the connecting edge has a second diameter greater than the first diameter of the base, and 
 wherein the disc portion has a third diameter greater than or equal to the second diameter of the connecting edge of the truncated-cone portion. 
 
     
     
       19. The apparatus of  claim 18 , wherein the apparatus is configured to maintain the second coolant fluid at lower temperature than the first coolant fluid. 
     
     
       20. The apparatus of  claim 18 , wherein the first coolant fluid comprises water.